The primary mission ofthe MMPC-UCD Body Composition, Thermoregulation, and Food Intake Behavior Core is to provide our clients with in-depth assessements of molecular and whole-animal phenomena relevant to body weight regulation and metabolism. In addition to providing essential basic metabolic phenotyping services and expertise, the Core has a unique strength in the application of challenge tests designed to unmask subtle phenotypes associated with energy balance and gut function. In addition, the Core will conduct pilot and feasibility studies with a goal to institute new mouse phenotyping approaches that will be useful to the MMPC-UCD and the MMPC system as a whole. Investigators participating in this Core have proven capabilities in studying mouse thermogenesis, adipose tissue biology, and energy balance regulators including gut signals. The MMPC-UCD Body Composition, Thermoregulation, and Food Intake Behavior Core will employ assays that complement and extend those offered by existing MMPCs, using state-of-the-art approaches and a unique perspective that includes an appreciation ofthe roles of gut physiology and peripheral neuron function.